Functionalized Porous Polymer Networks as High-Performance PFAS Adsorbents

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Per- and polyfluoroalkyl substances (PFAS) are ubiquitous environmental contaminants with potential health risks.
• Low concentrations of PFAS in water make their removal challenging using conventional methods.
• Existing adsorbents often suffer from low selectivity, capacity, and slow adsorption kinetics.

Purpose of the Study:

• To develop and optimize adsorbent materials for efficient PFAS removal.
• To investigate the role of various chemical interactions in PFAS adsorption.
• To create a highly selective and reusable adsorbent for PFAS remediation.

Main Methods:

• Post-synthetic modification of a porous polymer network (PPN-6) with diverse chemical moieties.
• Batch adsorption experiments to evaluate PFAS removal performance.
• Computational studies to elucidate adsorption mechanisms.
• Desorption and recycling studies to assess material reusability.

Main Results:

• Adsorption is driven by electrostatic and hydrogen-bonding for short-chain PFAS, and hydrophobic/fluorophilic interactions for long-chain PFAS.
• A fluorinated alkylammonium-functionalized PPN-6 (PPN-6-FNDMB) showed high capacity (4.0 mmol/g) and rapid kinetics (<30 s).
• PPN-6-FNDMB achieved near-complete removal of 21 PFAS from contaminated groundwater and demonstrated effective desorption and reuse over four cycles.

Conclusions:

• Chemical functionalization of porous polymer networks significantly enhances PFAS adsorption.
• PPN-6-FNDMB represents a highly effective adsorbent for PFAS removal, outperforming commercial alternatives.
• The developed material offers a promising solution for PFAS remediation and concentration from contaminated water sources.